I'm in the US, does this matter?you may need to change the car iphone kit to something similar to this:
Thank YouJust to let you know that you are not alone, and also, to bump this thread in case something has come up.
I've been reading forums that range from 2008-2012 all dealing with the exact same issue.
A VERY interesting piece of information I came across: When using the app "Viber" for calls, the audio is actually routed through your stereo! This is a quick fix, but for me Viber is not perfectly reliable for voice calls, so I'd like to see a fix for iPhone's native phone app.
However, what it does show is something VERY important: that this is a software issue and a jailbreak tweak would do the trick!